Java — 140 Operations for AI Agents
This page is the canonical reference an AI coding agent uses to refactor, query, and analyze Java code through the act MCP server. 140 operations available: 66 refactor, 18 query, 42 analysis, 14 verification. Each operation is callable from Claude Code, Cursor, Codex, OpenCode, or any MCP-compatible agent host. Click any operation for a stable anchor link suitable for citation.
Query
18 query tools, the same on every supported language. Descriptions live in the shared reference: /docs/query-tools.
callers control_flow data_flow definition diagnostics effect_closure effect_summary fix_auto get_type graph import_organize interface mutations references repo_outline skeleton symbols symbols_batch
Refactor
| Operation | Description |
|---|---|
add-explicit-type |
Replace a `var` local declaration with its inferred explicit type |
add-final-modifier |
Add final modifier for immutability |
add-interface-implementation |
Add interface implementation to a class |
add-null-check |
Wrap expression in null-check guard |
add-parameter-from-field |
Add a method parameter sourced from a field |
add-static-modifier |
Add static modifier when applicable |
add-visibility-modifier |
Add explicit public/private/protected modifier |
change-method-signature |
Modify a method's parameter list or return type |
change-signature |
Modify function parameters, return, generics |
convert-anonymous-class-to-lambda |
Convert single-method anonymous class to lambda |
convert-anonymous-to-class |
Extract an anonymous class into a named top-level or nested class |
convert-enhanced-for |
Convert traditional for to enhanced for loop |
convert-if-to-ternary |
Convert if-else to ternary operator |
convert-string-concat-to-builder |
Convert string concatenation in loops to StringBuilder |
convert-to-builder |
Generate a Builder pattern for a class |
convert-to-enum |
Convert a class with constant fields to an enum |
convert-to-lambda |
Convert anonymous inner class to lambda |
convert-to-object-initializer |
Replace constructor chaining with an object initializer block |
decrease-visibility |
Decrease visibility for encapsulation |
encapsulate |
Make field private, generate getter/setter |
encapsulate-field |
Make a field private and generate getter/setter |
expand-visibility |
Widen the visibility modifier of a declaration |
extract-class |
Extract methods/fields to new class |
extract-constant |
Extract value to named constant |
extract-interface |
Extract method signatures into new interface |
extract-superclass |
Pull common members into a new superclass |
extract-variable |
Extract expression into new local variable |
extract_function |
Extract a code selection into a new function — automatically infers parameters, return types, and inserts the call site. Use instead of manually cutting/pasting code. Works without LSP; LSP improves type inference. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool), receipt (bool)] |
extract_variable |
Extract an expression into a named variable — inserts the declaration and replaces the expression with the variable name. Works without LSP. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool)] |
generate-constructor |
Create constructor with field initialization |
generate-equals-method |
Generate equals() and hashCode() implementation |
generate-getter |
Create getter method for field |
generate-getters-setters |
Create both getter and setter for field |
generate-implementation |
Create class implementing interface |
generate-javadoc |
Create javadoc comment block |
generate-override-annotation |
Add @Override annotation to overridden methods |
generate-setter |
Create setter method for field |
generate-tostring-method |
Create toString() implementation |
generify-variable |
Replace a raw type variable with a generic type parameter |
increase-visibility |
Increase visibility when needed |
inline |
Inline a variable, function, or method — replace every usage with its definition body, then remove the original. The inverse of extract. Works without LSP (single-file); LSP enables cross-file inlining. Params: file (string), symbol (string) [, line (u32), preview (bool), receipt (bool)] |
inline-variable |
Replace variable with its assignment |
insert_body |
Replace a function's implementation body with new code. AST-validated — rejects if the result has parse errors, so you can't accidentally break syntax. Use instead of manual text editing for function rewrites. Params: file (string), symbol (string), code (string) [, commit (bool)] |
introduce-interface |
Extract a new interface from an existing class |
introduce-method |
Wrap statements into new method |
introduce-parameter |
Convert local variable to method parameter |
introduce-variable |
Extract an expression into a named local variable |
merge-variable-declaration |
Merge a variable declaration and its first assignment into one statement |
move-method-up |
Move a method to the superclass |
move_symbol |
Move a function, class, or type to a different file and automatically update all imports across the codebase. Use instead of manually cut/paste + fixing imports. Works without LSP (single-file); LSP enables cross-file import updates. Params: file (string), symbol (string), destination (string) [, preview (bool), receipt (bool)] |
organize-imports |
Sort and deduplicate import statements |
pull-up-method |
Pull a method from a subclass into the superclass hierarchy |
push-down-method |
Move a method from a superclass down to subclasses |
recipe_run |
Run a codemod recipe: declarative match → transform → optional verify across modeled grammars. Preview lists matches; apply writes with optional E7 receipts and all-or-nothing rollback. Returns a per-site report. |
remove-redundant-cast |
Delete unnecessary type cast |
remove-redundant-modifiers |
Delete modifiers that are implied by context |
remove-unused-field |
Delete field that is never read |
remove-unused-import |
Delete unused import statement |
remove-unused-method |
Delete method that is never called |
rename |
Rename a symbol and automatically update ALL references across the codebase. Safer and faster than find-and-replace — AST-aware, won't rename strings or comments. Works without LSP (single-file); LSP enables cross-file renames. Params: file (string), old_name (string), new_name (string) [, line (u32), column (u32), preview (bool), receipt (bool)] |
rename |
Rename symbol and all references |
reorder-parameters |
Change the order of method parameters |
simplify-field-initialization |
Move a field initializer from the constructor into the field declaration |
simplify-lambda |
Convert a verbose lambda to a method reference where possible |
split-variable-declaration |
Split a combined variable declaration and assignment into separate statements |
wrap-method-body |
Wrap a method body in a try/catch, synchronized, or other block |
Analysis
42 analysis tools, the same on every supported language. Descriptions live in the shared reference: /docs/analysis-tools.
analyze_api_diff analyze_chokepoints analyze_clones analyze_clusters analyze_cohesion analyze_conformance analyze_coupling analyze_cycle_risk analyze_cycles analyze_dead_code analyze_depth analyze_entry_points analyze_export analyze_extraction analyze_fan_balance analyze_features analyze_hotspots analyze_impact analyze_inconsistencies analyze_inheritance analyze_interface_bloat analyze_interfaces analyze_layers analyze_orphan_types analyze_patterns analyze_platform_deps analyze_readiness analyze_roles analyze_seams analyze_stability analyze_surface analyze_test_gaps analyze_thickness analyze_type_completeness churn_hotspots co_change_clusters coverage_overlay ownership_map profile_overlay simulate split_module trace_overlay
Verify
14 verify tools, the same on every supported language. Descriptions live in the shared reference: /docs/verification.
bisect_regression gate generate_test_harness scan secret_surface summarize_pr taint_flow unsafe_surface verify_behavioral_equivalence verify_contract_preserved verify_diff_semantics verify_port_parity verify_side_effects verify_test_impact